1 . The man didn’t know ______ the thief broke into the house and stole all his valuable things.

A．it was when that

B．when it was that

C．that it was when

2 . It was _____ he came back from Africa that year _________ he met the girl he would like to marry.

A．when; then

B．not; until

C．not until; that

D．only; when

3 . Up till now, there has been no scientific evidence about ________ caused the death of dinosaurs.

A．what is it that

B．what it was that

C．it was what

D．what is it

4 . —Was it at 11 o'clock________your father came back last night? (用适当的单词填空)
—Yes, he is always coming back so late.

5 . — Today Mary is in low spirits.
— Yes, but she won’t say _______ bothers her.

A．why is it that	B．that is why
C．it is what	D．what it is that

6 . ________ the catastrophe happened that the local government realized the importance of substantial development.

A．It was until	B．Not until
C．Until	D．It was not until

7 . Which of the following is Wrong?

A．But for his help, I wouldn’t have done such a wonderful job in English.

B．His house, all the windows of which face south, enjoys great sunshine.

C．Not until the result turned out to be so serious that he realized his fault.

D．It is at this moment that he made the most important decision in his life.

8 . Who was it________played a trick on the new English teacher? (用适当的单词填空)

9 . —What do you think it is________has brought worldwide attention to China? (用适当的单词填空)
—Rapid and steady economic growth, of course.

10 . It is in fifty years        China will become one of the most                countries in the world.

A．that: developed	B．since:   developed
C．when; developing	D．before; developing